﻿/*
 * jQuery pager plugin
 * Version 1.0 (12/22/2008)
 * @requires jQuery v1.2.6 or later
 *
 * Example at: http://jonpauldavies.github.com/JQuery/Pager/PagerDemo.html
 *
 * Copyright (c) 2008-2009 Jon Paul Davies
 * Dual licensed under the MIT and GPL licenses:
 * http://www.opensource.org/licenses/mit-license.php
 * http://www.gnu.org/licenses/gpl.html
 * 
 * Read the related blog post and contact the author at http://www.j-dee.com/2008/12/22/jquery-pager-plugin/
 *
 * This version is far from perfect and doesn't manage it's own state, therefore contributions are more than welcome!
 *
 * Usage: .pager({ pagenumber: 1, pagecount: 15, buttonClickCallback: PagerClickTest });
 *
 * Where pagenumber is the visible page number
 *       pagecount is the total number of pages to display
 *       buttonClickCallback is the method to fire when a pager button is clicked.
 *
 * buttonClickCallback signiture is PagerClickTest = function(pageclickednumber) 
 * Where pageclickednumber is the number of the page clicked in the control.
 *
 * The included Pager.CSS file is a dependancy but can obviously tweaked to your wishes
 * Tested in IE6 IE7 Firefox & Safari. Any browser strangeness, please report.
 */
(function($) {

	$.fn.pager = function(options) {

		var opts = $.extend({}, $.fn.pager.defaults, options);

		return this.each(function() {

			// empty out the destination element and then render out the pager
			// with the supplied options

			$(this).empty().append(
					renderpager(parseInt(options.pagenumber),
							parseInt(options.pagecount),
							parseInt(options.pagesize),
							options.buttonClickCallback)).append(
					"<div class='clear'></div>");

		});
	};

	// render and return the pager with the supplied options
	function renderpager(pagenumber, pagecount, pagesize, buttonClickCallback) {

		// setup $pager to hold render
		var $pager = $('<ul class="floatr"></ul>');

		// add in the previous and next buttons
		$pager.append(renderButton('prev', pagenumber, pagecount,
				buttonClickCallback));

		// pager currently only handles 10 viewable pages ( could be easily
		// parameterized, maybe in next version ) so handle edge cases
		var startPoint = 1;
		var endPoint = 9;

		if (pagenumber > 4) {
			startPoint = pagenumber - 4;
			endPoint = pagenumber + 4;
		}

		if (endPoint > pagecount) {
			startPoint = pagecount - 8;
			endPoint = pagecount;
		}

		if (startPoint < 1) {
			startPoint = 1;
		}

		// loop thru visible pages and render buttons
		for ( var page = startPoint; page <= endPoint; page++) {

			var currentButton = $('<li class="page-number"><a href="javascript:void(0);">'
					+ (page) + '</a></li>');

			page == pagenumber ? currentButton.addClass('current')
					: currentButton.click(function() {
						buttonClickCallback($(this).children("a").html());
					});
			currentButton.appendTo($pager);
		}

		// render in the next and last buttons before returning the whole
		// rendered control back.
		$pager.append(renderButton('next', pagenumber, pagecount,
				buttonClickCallback));
		var $select = $("<li class='show'><select name='numPerPage'></select></li>");
		var pagesizes = [ 20, 30, 50 ];
		for ( var i = 0; i < pagesizes.length; i++) {
			if (pagesizes[i] == pagesize) {
				$select.find("select").append(
						"<option selected='selected'>" + pagesizes[i]
								+ "</option>");
			} else {
				$select.find("select").append(
						"<option>" + pagesizes[i] + "</option>");
			}

		}
		$pager.append($select);
		return $pager;
	}

	// renders and returns a 'specialized' button, ie 'next', 'previous' etc.
	// rather than a page number button
	function renderButton(buttonLabel, pagenumber, pagecount,
			buttonClickCallback) {

		var $Button = $('<li class="pgNext"><a href="javascript:void(0);">'
				+ buttonLabel + '</a></li>');

		var destPage = 1;

		// work out destination page for required button type
		switch (buttonLabel) {
		case "<<":
			destPage = 1;
			break;
		case "prev":
			destPage = pagenumber - 1;
			break;
		case "next":
			destPage = pagenumber + 1;
			break;
		case ">>":
			destPage = pagecount;
			break;
		}

		// disable and 'grey' out buttons if not needed.
		if (buttonLabel == "<<" || buttonLabel == "prev") {
			pagenumber <= 1 ? $Button.addClass('pgEmpty') : $Button
					.click(function() {
						buttonClickCallback(destPage);
					});
		} else {
			pagenumber >= pagecount ? $Button.addClass('pgEmpty') : $Button
					.click(function() {
						buttonClickCallback(destPage);
					});
		}

		return $Button;
	}

	// pager defaults. hardly worth bothering with in this case but used as
	// placeholder for expansion in the next version
	$.fn.pager.defaults = {
		pagenumber : 1,
		pagecount : 1,
		pagesize : 20
	};

})(jQuery);
